Cardiovascular Effects of Long-Term Exposure to Air Pollution: A Population-Based Study With 900 845 Person-Years of Follow-up

Effect Modification of Heat-Related Mortality Risk by Air Pollutants in Shandong, China

Although studies have reported the modification effect of air pollutants on heat-related health risk, little is known on the modification effect among various particulate matter with different particle size on mortality. We aimed to investigate whether the associations of hot temperatures with daily mortality were modified by different air pollutant levels in Shandong Province, China. Daily data of air pollutants, meteorological factors, and mortality of 1,822 subdistricts in Shandong province from 2013 to 2018 were collected. We used a time-stratified case-crossover model with an interaction term between the cross-basis term for ambient temperature and the linear function of particulate matter ≤1 µm (PM1), PM2.5, nitrogen dioxide (NO2), and ozone to obtain heat-mortality associations during the hot season. Results showed that the cumulative odds ratio of extreme heat on mortality over 0 to 10 days was 3.66 (95% CI: 3.10-4.31). The mortality risk during hot seasons was stronger at high air pollutant levels. The modification effect of particulate matters on heat-related mortality decreased by its aerodynamic diameter. Females and older adults over 75 years were more vulnerable to the modification effect of air pollutants, and significant differences were detected in the association between temperatures and mortality stratified by PM1 and PM2.5. Higher heat-related mortality risks were observed at high NO2 levels, especially for cardiorespiratory disease. The findings suggest that more consideration should be given to the combined effect of very fine particles and NO2 with ambient heat when developing healthcare strategies, and women and older adults should be given priority in health-related settings.

Age and sex differences in the effects of short- and long-term exposure to air pollution on endothelial dysfunction

BACKGROUND

The effects of air pollution on endothelial function remain unclear across populations. We aimed to use brachial artery flow-mediated dilatation (FMD) to identify demographic differences in the effects of air pollution exposure on endothelial dysfunction.

METHODS

We measured FMD in 850 participants from October 2016 to January 2020. Location-specific concentrations of fine particulate matter < 2.5 μm aerodynamic diameter (PM2.5), inhalable particulate matter < 10 μm aerodynamic diameter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) measured by fixed ambient air monitoring stations were collected for short- and long-term exposure assessment. Multiple linear regression models and restricted cubic splines were used to assess the associations before and after stratification by age and sex.

RESULTS

This study eventually included 828 participants [551 (66.5%) younger than 65 years and 553 (66.8%) men]. Each 10 µg/m3 increase in 7-day exposure to PM2.5 and PM10 was significantly linearly associated with a 0.07% (β = -0.07, 95% CI: -0.13 to -0.004) and 0.05% (β = -0.05, 95% CI: -0.10 to -0.004) decrease in FMD in the fully adjusted model. After full adjustment, long-term exposure to all air pollutants was significantly associated with impaired FMD. Each 10 µg/m3 increase in long-term exposure to PM2.5 and PM10 was significantly associated with a -0.18% (95% CI: -0.34 to -0.03) and - 0.23% (95% CI: -0.40 to -0.06) change in FMD, respectively. After stratification, the associations of lower FMD with long-term exposure to PM2.5, PM10, SO2, NO2, and CO significantly persisted in men and participants younger than 65 years instead of women or older participants. For short-term exposure, we observed differences consistent with long-term exposure and a stronger effect of 7-day exposure to SO2 in men due to a significant interaction effect.

CONCLUSION

Short- and long-term exposure to different air pollutants are strongly associated with decreased endothelial function, and susceptibility to air pollution varies significantly with age and sex.

Greenness mitigate cause-specific mortality associated with air pollutants in ischemic and hemorrhagic stroke patients: An ecological health cohort study

BACKGROUND

Air pollution is one of the most serious environmental risks to mortality of stroke. However, there exists a noteworthy knowledge gap concerning the different stroke subtypes, causes of death, the susceptibility of stroke patient, and the role of greenness in this context.

METHODS

We analyzed data from an ecological health cohort, which included 334,261 patients aged ≥40 years with stroke (comprising 288,490 ischemic stroke and 45,771 hemorrhagic stroke) during the period 2013-2019. We used Cox proportional hazards models with time-varying exposure to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to assess the associations of annual average fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) with both all-cause and cause-specific mortality. Additionally, we conducted analyses to examine the effect modification by greenness and identify potential susceptibility factors through subgroup analyses.

RESULT

In multivariable-adjusted models, long-term exposure to PM2.5 and NO2 was associated with increased risk of all-cause mortality (HR: 1.038, 95% CI: 1.029-1.047 for PM2.5; HR: 1.055, 95% CI: 1.026-1.085 for NO2, per 10 μg/m3, for ischemic stroke patients; similar for hemorrhagic stroke patients). Gradually increasing effect sizes were shown for CVD mortality and stroke mortality. The HRs of mortality were slightly weaker with high versus low vegetation exposure. Cumulative exposures increased the HRs of pollutant-related mortality, and greater greenness decreased this risk. Two subtypes of stroke patients exhibited diverse patterns of benefit.

CONCLUSION

Increasing residential greenness attenuates the increased risk of mortality with different patterns due to chronic air pollutants for ischemic and hemorrhagic stroke, offering valuable insights for precise tertiary stroke prevention strategies.

Travel Distance Between Participants in US Telemedicine Sessions With Estimates of Emissions Savings: Observational Study

BACKGROUND

Digital health and telemedicine are potentially important strategies to decrease health care's environmental impact and contribution to climate change by reducing transportation-related air pollution and greenhouse gas emissions. However, we currently lack robust national estimates of emissions savings attributable to telemedicine.

OBJECTIVE

This study aimed to (1) determine the travel distance between participants in US telemedicine sessions and (2) estimate the net reduction in carbon dioxide (CO2) emissions attributable to telemedicine in the United States, based on national observational data describing the geographical characteristics of telemedicine session participants.

METHODS

We conducted a retrospective observational study of telemedicine sessions in the United States between January 1, 2022, and February 21, 2023, on the doxy.me platform. Using Google Distance Matrix, we determined the median travel distance between participating providers and patients for a proportional sample of sessions. Further, based on the best available public data, we estimated the total annual emissions costs and savings attributable to telemedicine in the United States.

RESULTS

The median round trip travel distance between patients and providers was 49 (IQR 21-145) miles. The median CO2 emissions savings per telemedicine session was 20 (IQR 8-59) kg CO2). Accounting for the energy costs of telemedicine and US transportation patterns, among other factors, we estimate that the use of telemedicine in the United States during the years 2021-2022 resulted in approximate annual CO2 emissions savings of 1,443,800 metric tons.

CONCLUSIONS

These estimates of travel distance and telemedicine-associated CO2 emissions costs and savings, based on national data, indicate that telemedicine may be an important strategy in reducing the health care sector's carbon footprint.

The key characteristics of cardiotoxicity for the pervasive pollutant phenanthrene

The key characteristic (KCs) framework has been used previously to assess the carcinogenicity and cardiotoxicity of various chemical and pharmacological agents. Here, the 12 KCs of cardiotoxicity are used to evaluate the previously reported cardiotoxicity of phenanthrene (Phe), a tricyclic polycyclic aromatic hydrocarbon (PAH), and major component of fossil fuel-derived air pollution. Phe is a semi-volatile pollutant existing in both the gas phase and particle phase through adsorption onto or into particulate matter (PM). Phe can translocate across the airways and gastrointestinal tract into the systemic circulation, enabling body-wide effects. Our evaluation based on a comprehensive literature review, indicates Phe exhibits 11 of the 12 KCs for cardiotoxicity. These include adverse effects on cardiac electromechanical performance, the vasculature and endothelium, immunomodulation and oxidative stress, and neuronal and endocrine control. Environmental agents that have similarly damaging effects on the cardiovascular system are heavily regulated and monitored, yet globally there is no air quality regulation specific for PAHs like Phe. Environmental monitoring of Phe is not the international standard with benzo[a]pyrene being frequently used as a proxy despite the two PAH species exhibiting significant differences in sources, concentration variations and toxic effects. The evidence summarised in this evaluation highlights the need to move away from proxied PAH measurements and develop a monitoring network capable of measuring Phe concentration. It also stresses the need to raise awareness amongst the medical community of the potential cardiovascular impact of PAH exposure. This will allow the production of mitigation strategies and possibly the development of new policies for the protection of the societal groups most vulnerable to cardiovascular disease.

Association between PM10 exposure and risk of myocardial infarction in adults: A systematic review and meta-analysis

BACKGROUND

Air pollution has several negative health effects. Particulate matter (PM) is a pollutant that is often linked to health adversities. PM2.5 (PM with an aerodynamic diameter of ≤2.5μm) exposure has been associated with negative cardiovascular (CV) outcomes. However, the impact of PM10 (PM with an aerodynamic diameter of ≤10μm) exposure is often overlooked due to its limited ability to pass the alveolar barrier. This study aims to assess the association between PM10 exposure and risk of myocardial infarction (MI) amongst adults (≥18 years of age) as this has been poorly studied.

METHODS

The study protocol was published on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023409796) on March 31, 2023. Literature searches were conducted on 4 databases (Ovid Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Web of Science) on January 17, 2023, for studies looking at associations between PM and MI. English studies from all time periods were assessed. Studies selected for review were time-series, case-crossover, and cohort studies which investigated the risk of MI as an outcome upon PM10 exposure. The quality of evidence was assessed using Cochrane's Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Data for different risk outcomes (risk ratio (RR), odds ratio (OR), hazard ratio (HR)) and 3 lags was meta-analyzed using an inverse variance statistical analysis using a random effects model. The pooled effect sizes and the 95% confidence intervals (CIs) were reported in forest plots.

RESULTS

Among the 1,099 studies identified, 41 were included for review and 23 were deemed eligible for meta-analysis. Our analysis revealed that there is an increased risk (OR = 1.01; 95% CI:1.00-1.02) of MI with a 10 μg/m3 increase in PM10 after a lag 0 and lag 1 delay.

CONCLUSIONS

Our findings indicate that PM10 exposure is associated with an increased risk of MI. This can aid in informing environmental policy-making, personal-level preventative measures, and global public health action.

Nationwide estimation of daily ambient PM2.5 from 2008 to 2020 at 1 km2 in India using an ensemble approach

High-resolution assessment of historical levels is essential for assessing the health effects of ambient air pollution in the large Indian population. The diversity of geography, weather patterns, and progressive urbanization, combined with a sparse ground monitoring network makes it challenging to accurately capture the spatiotemporal patterns of ambient fine particulate matter (PM2.5) pollution in India. We developed a model for daily average ambient PM2.5 between 2008 and 2020 based on monitoring data, meteorology, land use, satellite observations, and emissions inventories. Daily average predictions at each 1 km × 1 km grid from each learner were ensembled using a Gaussian process regression with anisotropic smoothing over spatial coordinates, and regression calibration was used to account for exposure error. Cross-validating by leaving monitors out, the ensemble model had an R2 of 0.86 at the daily level in the validation data and outperformed each component learner (by 5-18%). Annual average levels in different zones ranged between 39.7 μg/m3 (interquartile range: 29.8-46.8) in 2008 and 30.4 μg/m3 (interquartile range: 22.7-37.2) in 2020, with a cross-validated (CV)-R2 of 0.94 at the annual level. Overall mean absolute daily errors (MAE) across the 13 years were between 14.4 and 25.4 μg/m3. We obtained high spatial accuracy with spatial R2 greater than 90% and spatial MAE ranging between 7.3-16.5 μg/m3 with relatively better performance in urban areas at low and moderate elevation. We have developed an important validated resource for studying PM2.5 at a very fine spatiotemporal resolution, which allows us to study the health effects of PM2.5 across India and to identify areas with exceedingly high levels.

Exposure-response associations between chronic exposure to fine particulate matter and risks of hospital admission for major cardiovascular diseases: population based cohort study

OBJECTIVE

To estimate exposure-response associations between chronic exposure to fine particulate matter (PM2.5) and risks of the first hospital admission for major cardiovascular disease (CVD) subtypes.

DESIGN

Population based cohort study.

SETTING

Contiguous US.

PARTICIPANTS

59 761 494 Medicare fee-for-service beneficiaries aged ≥65 years during 2000-16. Calibrated PM2.5 predictions were linked to each participant's residential zip code as proxy exposure measurements.

MAIN OUTCOME MEASURES

Risk of the first hospital admission during follow-up for ischemic heart disease, cerebrovascular disease, heart failure, cardiomyopathy, arrhythmia, valvular heart disease, thoracic and abdominal aortic aneurysms, or a composite of these CVD subtypes. A causal framework robust against confounding bias and bias arising from errors in exposure measurements was developed for exposure-response estimations.

RESULTS

Three year average PM2.5 exposure was associated with increased relative risks of first hospital admissions for ischemic heart disease, cerebrovascular disease, heart failure, cardiomyopathy, arrhythmia, and thoracic and abdominal aortic aneurysms. For composite CVD, the exposure-response curve showed monotonically increased risk associated with PM2.5: compared with exposures ≤5 µg/m3 (the World Health Organization air quality guideline), the relative risk at exposures between 9 and 10 µg/m3, which encompassed the US national average of 9.7 µg/m3 during the study period, was 1.29 (95% confidence interval 1.28 to 1.30). On an absolute scale, the risk of hospital admission for composite CVD increased from 2.59% with exposures ≤5 µg/m3 to 3.35% at exposures between 9 and 10 µg/m3. The effects persisted for at least three years after exposure to PM2.5. Age, education, accessibility to healthcare, and neighborhood deprivation level appeared to modify susceptibility to PM2.5.

CONCLUSIONS

The findings of this study suggest that no safe threshold exists for the chronic effect of PM2.5 on overall cardiovascular health. Substantial benefits could be attained through adherence to the WHO air quality guideline.

Associations between short-term exposure to ambient PM2.5 and incident cases of cardiovascular disease in Yantai, China

There are limited studies investigating the association between short-term exposure to PM2.5 and incident cardiovascular disease (CVD) cases in China. This study aims to examine the short-term effects of PM2.5 on the incidence of cardiovascular diseases. A combination of Poisson-distribution generalized linear model and distributed lag non-linear model was used to examine the association between short-term exposure to PM2.5 and incident cases of CVD. The results revealed that per 10 µg/m3 increment of PM2.5 would increase the incident CVD cases by 0.147% (Relative Risk: 1.00147, 95% Confidence Interval: 1.00008-1.00286) at a lag of 2 days. The stratified analyses showed higher effects risk in females, older residents (aged 60-75 years), and acute myocardial infarction group (p-value for difference <0.05). This study indicates that short-term exposure to PM2.5 may increase the risk of CVD and highlights the necessity for a higher air quality standard in Yantai, China.

Long-term NO2 exposure and mortality: A comprehensive meta-analysis

In response to the World Health Organization's (WHO) revised annual mean nitrogen dioxide (NO2) standard from 40 μg/m3 to 10 μg/m3, reflecting the growing evidence linking long-term exposure to ambient NO2 and excess mortality, we conducted a comprehensive meta-analysis incorporating 11 new studies published since the WHO analysis. Our investigation involved a systematic search of three major databases (PubMed, Web of Science, and Scopus) for articles published until July 1, 2022. We employed random effects models to calculate summarized risk ratios (RR) along with 95% confidence intervals (CIs) for overall and subgroup analyses. Sensitivity analyses were conducted to assess result robustness, and publication bias was evaluated using funnel plots and Egger's linear regression. Out of 2799 identified articles, 56 were included in our meta-analysis. The findings indicate a heightened risk of all-cause, cardiovascular, and respiratory mortality associated with long-term exposure to ambient NO2, with pooled RR values of 1.03 (95% CI: 1.02, 1.05), 1.07 (95% CI: 1.04, 1.10), and 1.03 (95% CI: 1.02, 1.05) per 10 μg/m3 increase, respectively. Substantial heterogeneity (I2 = 84%-96%) among studies was observed. Subgroup analysis revealed significantly elevated RR values in Asia and Oceania (p-value <0.05). The aggregated values for all-cause and cardiovascular mortality were slightly larger than those reported in previous studies. Our study emphasizes the imperative to develop more patient cohorts and conduct age-refined analyses to explore the impact of existing chronic diseases on these associations. Further, additional cohorts in Asia and Oceania are essential to fortify evidence in these regions. Lastly, we recommend using fused multi-source data with higher spatiotemporal resolution for individual exposure representation to minimize heterogeneity among studies in future research.

Association between long-term exposure to ambient air pollution and lesion ischemia in patients with atherosclerosis

BACKGROUND AND AIMS

Air pollution has been associated with coronary artery disease. The underlying mechanisms were understudied, especially in relation to coronary stenosis leading to myocardial ischemia. Advances in computed tomography (CT) allow for novel quantification of lesion ischemia. We aim to investigate associations between air pollution exposures and fractional flow reserve on CT (CT-FFR), a measure of coronary artery blood flow.

METHODS

CT-FFR, which defines a ratio of maximal myocardial blood flow compared to its normal value (range: 0-100%), was characterized in 2017 patients with atherosclerosis between 2015 and 2017. Exposures to ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM2.5) were estimated using high-resolution exposure models. Linear and logistic regression models were used to assess the association of each air pollutant with CT-FFR and with the prevalence of clinically relevant myocardial ischemia (CT-FFR <75%).

RESULTS

Participants were on average 60.1 years old. Annual mean O3, NO2, PM2.5 were 61, 47 and 60 μg/m3, respectively. Mean CT-FFR value was 76.9%. In the main analysis, a higher level of O3 was associated with a lower CT-FFR value (-1.74%, 95% CI: -2.85, -0.63 per 8 μg/m3) and a higher prevalence of myocardial ischemia (odds ratio: 1.32, 95% CI: 1.05-1.65), adjusting for potential confounders such as risk factors and plaque phenotypes, independent of the effects of exposure to NO2 and PM2.5. No associations were observed for PM2.5 or NO2 with CT-FFR.

CONCLUSIONS

Long-term exposure to O3 is associated with lower CT-FFR value in atherosclerotic patients, indicating higher risk of lesion ischemia.

Air Pollution and Cardiac Diseases: A Review of Experimental Studies

Air pollution is associated with around 6.5 million premature deaths annually, which are directly related to cardiovascular diseases, and the most dangerous atmospheric pollutants to health are as follows: NO2, SO2, CO, and PM. The mechanisms underlying the observed effects have not yet been clearly defined. This work aims to conduct a narrative review of experimental studies to provide a more comprehensive and multiperspective assessment of how the effect of atmospheric pollutants on cardiac activity can result in the development of cardiac diseases. For this purpose, a review was carried out in databases of experimental studies, excluding clinical trials, and epidemiological and simulation studies. After analyzing the available information, the existence of pathophysiological effects of the different pollutants on cardiac activity from exposure during both short-term and long-term is evident. This narrative review based on experimental studies is a basis for the development of recommendations for public health.

Effect of Air Pollution Particulate Matter on Ischemic and Hemorrhagic Stroke: A Scoping Review

Air pollution particulate matter (PM) exposure has been established as a risk factor for stroke. However, few studies have investigated the effects of PM exposure on stroke subtypes (ischemic and hemorrhagic stroke). Ischemic (IS) and hemorrhagic strokes (HS) involve distinctive pathophysiological pathways and may be differentially influenced by PM exposure. This review aims to characterize the effects of PM exposure on ischemic and hemorrhagic strokes. It also identifies subpopulations that may be uniquely vulnerable to PM toxicity. Pubmed was queried from 2000 to 2023 to identify clinical and epidemiological studies examining the association between PM exposure and stroke subtypes (ischemic and hemorrhagic stroke). Inclusion criteria were: 1) articles written in English 2) clinical and epidemiological studies 3) studies with a clear definition of stroke, IS, HS, and air pollution 4) studies reporting the effects of PM and 5) studies that included distinct analyses per stroke subtype. Two independent reviewers screened the literature for applicable studies. A total of 50 articles were included in this review. Overall, PM exposure increases ischemic stroke risk in both lightly and heavily polluted countries. The association between PM exposure and hemorrhagic stroke is variable and may be influenced by a country's ambient air pollution levels. A stronger association between PM exposure and stroke is demonstrated in older individuals and those with pre-existing diabetes. There is no clear effect of sex or hypertension on PM-associated stroke risk. Current literature suggests PM exposure increases ischemic stroke risk, with an unclear effect on hemorrhagic stroke risk. Older patients and those with pre-existing diabetes may be the most vulnerable to PM toxicity. Future investigations are needed to characterize the influence of sex and hypertension on PM-associated stroke risk.

A Narrative Review on the Impact of Air Pollution on Heart Failure Risk and Exacerbation

Air pollution is a risk factor for many cardiovascular diseases, including heart failure (HF). Although the links between air pollution and HF have been explored, the results are scattered and difficult to piece together into a cohesive story. Therefore, we undertook a narrative review of all aspects of the relationship between HF and air pollution exposure, including risks of developing HF when exposed to air pollution, the exacerbation of HF symptoms by air pollution exposure, and the increased susceptibility that individuals with HF have for air pollution-related health risks. We also examined the literature on environmental justice as well as air pollution interventions for HF. We found substantial evidence linking air pollution exposure to HF incidence. There were a limited number of studies that examined air pollution exposure in clearly defined populations with HF to explore exacerbation of HF or the susceptibility of individuals with HF to air pollution health risks. However, there is substantial evidence that HF-related hospitalisations are increased under air pollution exposure and that the air pollution associated increase in HF-related hospitalisations is greater than hospitalisations for other chronic diseases, supporting links between air pollution and both exacerbation of HF and susceptibility of individuals with HF. There is emerging evidence for interventions that can decrease air pollution health risks for individuals with HF, and more studies are needed, particularly randomised controlled trials. Thus, although the air pollution-related health risks for HF incidence and hospitalisations are clear, further studies specifically targeted at identified data gaps will greatly improve our knowledge of the susceptibility of individuals with HF and interventions to reduce risks.

Fine particulate matter exposure and pediatric mental health outcomes: An integrative review

INTRODUCTION

Climate change is expected to worsen air pollution globally, which contributes to a multitude of negative health outcomes in humans.

AIM

The purpose of this integrative review is to examine the relationship between exposure to fine particulate matter (PM2.5 ) and mental health outcomes in children and adolescents.

METHODS

This review utilized Whittemore and Knafl's methodology for conducting an integrative review. After a thorough search of the literature, 17 articles were selected for this review and evaluated utilizing the Johns Hopkins Evidence Based Practice Appraisal Tool.

RESULTS

Of the 17 articles, all were quantitative observational study designs. The studies were then synthesized into four outcome themes. These themes included emergent and general psychiatric outcomes, neurodevelopmental disorders, stress and anxiety, and depression.

DISCUSSION

The strongest evidence supports a possible correlation between PM2.5 exposure and adolescent mental health outcomes, although there were some studies that contradicted these associations. While research on this topic is in its early stages, more needs to be conducted to determine causality with any of the associations presented to improve generalizability of the findings.

IMPLICATIONS FOR PRACTICE

Nurses must be aware of and part of the solution to address climate change and resulting air pollution, as it is a potentially significant threat to children's mental health in the 21st century.

Long-term exposure to low-concentration PM2.5 and heart disease in older men in Perth, Australia: The Health in Men Study

Exposure to particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) is associated with increased risk of heart disease, but less is known about the relationship at low concentrations. This study aimed to determine the dose-response relationship between long-term PM2.5 exposure and risk of incident ischemic heart disease (IHD), incident heart failure (HF), and incident atrial fibrillation (AF) in older men living in a region with relatively low ambient air pollution.

Methods

PM2.5 exposure was estimated for 11,249 older adult males who resided in Perth, Western Australia and were recruited from 1996 to 1999. Participants were followed until 2018 for the HF and AF outcomes, and until 2017 for IHD. Cox-proportional hazards models, using age as the analysis time, and adjusting for demographic and lifestyle factors were used. PM2.5 was entered as a restricted cubic spline to model nonlinearity.

Results

We observed a mean PM2.5 concentration of 4.95 μg/m3 (SD 1.68 μg/m3) in the first year of recruitment. After excluding participants with preexisting disease and adjusting for demographic and lifestyle factors, PM2.5 exposure was associated with a trend toward increased incidence of IHD, HF, and AF, but none were statistically significant. At a PM2.5 concentration of 7 μg/m3 the hazard ratio for incident IHD was 1.04 (95% confidence interval [CI] = 0.86, 1.25) compared with the reference category of 1 μg/m3.

Conclusions

We did not observe a significant association between long-term exposure to low-concentration PM2.5 air pollution and IHD, HF, or AF.

Incident risk and burden of cardiovascular diseases attributable to long-term NO2 exposure in Chinese adults

BACKGROUND

A number of studies suggested a nexus between long-term exposure to nitrogen dioxide (NO2) and the incidence of cardiovascular disease (CVD), while population-based cohort evidence in low- and middle-income countries was extensively sparse.

METHODS

We carried out an 8-year longitudinal study (2010-2018) in a nationwide dynamic cohort of 36,948 Chinese adult participants, who were free of CVD at baseline. Annual average estimates of NO2 exposure were predicted using a well-validated spatiotemporal model and assigned to study participants based on their residential counties. Considering death as a competing risk event, Fine-Gray competing risk models with time-varying exposures at an annual scale were used to quantify incident risks of overall CVD, hypertension, and stroke associated with a 10-μg/m3 rise in NO2 exposure. Using the meta-analysis approach, we performed a pooled analysis of hazard ratio (HR) drawn from this and prior multinational cohort studies for the assessment of attributable burden. NO2-attributable overall CVD incidents in China were evaluated by city and province for years 2010 and 2018, referring to a counterfactual exposure level of 10 μg/m3 (2021 World Health Organization [WHO] air quality guidelines). A decomposition method was used to decompose net change in NO2-attributable CVD incidents during 2010 and 2018 into 3 primary contributions of driving factors (i.e., changes in NO2 exposure, population size, and incidence rate).

RESULTS

A total of 4428 overall CVD events (hypertension 2448, stroke 1044) occurred during a median follow-up period of 6.1 years. Annual mean NO2 concentration from 2010 to 2018 was 20.0 μg/m3 (range: 6.9-57.4 μg/m3). An increase of 10-µg/m3 in NO2 was associated with an HR of 1.558 (95% confidence interval [CI]: 1.477, 1.642) for overall CVD, 1.521 (95% CI: 1.419, 1.631) for hypertension, and 1.664 (95% CI: 1.485, 1.865) for stroke. Longitudinal associations of NO2 exposure with incident CVD were nearly linear over the exposure range, suggesting no discernible thresholds. Subgroup analyses indicated significantly higher NO2-associated risks of incident CVD among urban residents and overweight/obese individuals. According to pooled HR of NO2-CVD association (1.108, 95% CI: [1.007, 1.219]) from 10 multinational cohort studies, we estimated totally 1.44 million incident CVD cases attributable to NO2 exposure in 2018, representing a substantial decrease of 0.41 million compared to the estimate in 2010 (1.85 million) in mainland of China. Nationally, from 2010 to 2018, the attributable incident cases greatly dropped by 22.4%, which was dominantly driven by declined NO2 concentration (-47.1%) that had offset far from the rise of CVD incidence rate (+19.6%) and population growth (+5.1%).

CONCLUSIONS

This study provided nationwide cohort evidence for elevated risks of CVD incidence associated with long-term ambient NO2 exposure among Chinese adults, particularly in urban areas and among overweight/obese individuals. Our findings highlighted that reducing NO2 exposure below 2021 WHO guideline could help prevent a substantial portion of incident CVD cases in China.

MXene-Decorated Nylon Mesh Filters for Improvement of Indoor Air Quality by PM2.5 Filtration

Air pollution is a problem that is increasing day by day and poses a threat on a global scale. Particulate matter (PM) is one of the air pollutants that is the biggest concern regarding air quality. In order to control PM pollution, highly effective air filters are required. This is especially necessary for PM with a diameter of less than 2.5 micrometers (PM_2.5), which poses a health risk to humans. In this study, we demonstrate for the first time the use of a two-dimensional titanium carbide (Ti₃C₂) MXene nanosheets-decorated nylon mesh (MDNM) as a low cost and highly efficient PM_2.5 filter. This study develops a proof-of-concept method to capture PM_2.5. Thanks to their high specific surface area and active surface-terminating groups, conductive MXene nanosheets have made nylon mesh filters promising candidates for air filtration. The developed filters used electrostatic force to capture PM_2.5 and showed high removal efficiency (90.05%) when an ionizer was used and under an applied voltage of 10 V, while a commercial high-efficiency particulate air (HEPA) filter had a removal efficiency of 91.03% measured under identical conditions. The proposed filters, which stand out with their low energy consumption, low pressure drop (∼14 Pa), and cost-effectiveness, have the potential to be a strong competitor to conventional PM filter systems used in many fields.

Effect of Air Pollution on Heart Failure: Systematic Review and Meta-Analysis

BACKGROUND

Heart failure (HF) poses a significant global disease burden. The current evidence on the impact of air pollution on HF remains inconsistent.

OBJECTIVES

We aimed to conduct a systematic review of the literature and meta-analysis to provide a more comprehensive and multiperspective assessment of the associations between short- and long-term air pollution exposure and HF from epidemiological evidences.

METHODS

Three databases were searched up to 31 August 2022 for studies investigating the association between air pollutants (PM 2.5 , PM 10 , NO 2 , SO 2 , CO, O 3 ) and HF hospitalization, incidence, or mortality. A random effects model was used to derive the risk estimations. Subgroup analysis was conducted by geographical location, age of participants, outcome, study design, covered area, the methods of exposure assessment, and the length of exposure window. Sensitivity analysis and adjustment for publication bias were performed to test the robustness of the results.

RESULTS

Of 100 studies covering 20 countries worldwide, 81 were for short-term and 19 were for long-term exposure. Almost all air pollutants were adversely associated with the risk of HF in both short- and long-term exposure studies. For short-term exposures, we found the risk of HF increased by 1.8% [relative risk ( RR ) = 1.018 , 95% confidence interval (CI): 1.011, 1.025] and 1.6% (RR = 1.016 , 95% CI: 1.011, 1.020) per 10 - μ g / m 3 increment of PM 2.5 and PM 10 , respectively. HF was also significantly associated with NO 2 , SO 2 , and CO, but not O 3 . Positive associations were stronger when exposure was considered over the previous 2 d (lag 0-1) rather than on the day of exposure only (lag 0). For long-term exposures, there were significant associations between several air pollutants and HF with RR (95% CI) of 1.748 (1.112, 2.747) per 10 - μ g / m 3 increment in PM 2.5 , 1.212 (1.010, 1.454) per 10 - μ g / m 3 increment in PM 10 , and 1.204 (1.069, 1.356) per 10 -ppb increment in NO 2 , respectively. The adverse associations of most pollutants with HF were greater in low- and middle-income countries than in high-income countries. Sensitivity analysis demonstrated the robustness of our results.

DISCUSSION

Available evidence highlighted adverse associations between air pollution and HF regardless of short- and long-term exposure. Air pollution is still a prevalent public health issue globally and sustained policies and actions are called for to reduce the burden of HF. https://doi.org/10.1289/EHP11506.

Association of Long-Term Exposure to Ambient Fine Particulate Matter with Atherosclerotic Cardiovascular Disease Incidence Varies across Populations with Different Predicted Risks: The China-PAR Project

Previous studies have established a significant link between ambient fine particulate matter (PM_2.5) exposure and atherosclerotic cardiovascular disease (ASCVD) incidence, but whether this association varies across populations with different predicted ASCVD risks was uncertain previously. We included 109,374 Chinese adults without ASCVD at baseline from the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project. We obtained PM_2.5 data of participants' residential address from 2000 to 2015 using a satellite-based spatiotemporal model. Participants were classified into low-to-medium and high-risk groups according to the ASCVD 10-year and lifetime risk prediction scores. Hazard ratios (HRs) and 95% confidence intervals (CIs) for PM_2.5 exposure-related incident ASCVD, as well as the multiplication and additive interaction, were calculated using stratified Cox proportional hazard models. The additive interaction between risk stratification and PM_2.5 exposure was estimated by the synergy index (SI), the attributable proportion due to the interaction (API), and the relative excess risk due to interaction (RERI). Over the follow-up of 833,067 person-years, a total of 4230 incident ASCVD cases were identified. Each 10 μg/m³ increment of PM_2.5 concentration was associated with 18% (HR: 1.18; 95% CI: 1.14-1.23) increased risk of ASCVD in the total population, and the association was more pronounced among individuals having a high predicted ASCVD risk than those having a low-to-medium risk, with the HR (95% CI) of 1.24 (1.19-1.30) and 1.11 (1.02-1.20) per 10 μg/m³ increment in PM_2.5 concentration, respectively. The RERI, API, and SI were 1.22 (95% CI: 0.62-1.81), 0.22 (95% CI: 0.12-0.32), and 1.37 (95% CI: 1.16-1.63), respectively. Our findings demonstrate a significant synergistic effect on ASCVD between ASCVD risk stratification and PM_2.5 exposure and highlight the potential health benefits of reducing PM_2.5 exposure in Chinese, especially among those with high ASCVD risk.

Source-Specific Air Pollution Including Ultrafine Particles and Risk of Myocardial Infarction: A Nationwide Cohort Study from Denmark

BACKGROUND

Air pollution is negatively associated with cardiovascular health. Impediments to efficient regulation include lack of knowledge about which sources of air pollution contributes most to health burden and few studies on effects of the potentially more potent ultrafine particles (UFP).

OBJECTIVE

The authors aimed to investigate myocardial infarction (MI) morbidity and specific types and sources of air pollution.

METHODS

We identified all persons living in Denmark in the period 2005-2017, age >50 y and never diagnosed with MI. We quantified 5-y running time-weighted mean concentrations of air pollution at residencies, both total and apportioned to traffic and nontraffic sources. We evaluated particulate matter (PM) with aerodynamic diameter ≤2.5μm (PM2.5), <0.1μm (UFP), elemental carbon (EC), and nitrogen dioxide (NO2). We used Cox proportional hazards models, with adjustment for time-varying exposures, and personal and area-level demographic and socioeconomic covariates from high-quality administrative registers.

RESULTS

In this nationwide cohort of 1,964,702 persons (with 18 million person-years of follow-up and 71,285 cases of MI), UFP and PM2.5 were associated with increased risk of MI with hazard ratios (HRs) per interquartile range (IQR) of 1.040 [95% confidence interval (CI): 1.025, 1.055] and 1.053 (95% CI: 1.035, 1.071), respectively. HRs per IQR of UFP and PM2.5 from nontraffic sources were similar to the total (1.034 and 1.051), whereas HRs for UFP and PM2.5 from traffic sources were smaller (1.011 and 1.011). The HR for EC from traffic sources was 1.013 (95% CI: 1.003, 1.023). NO2 from nontraffic sources was associated with MI (HR=1.048; 95% CI: 1.034, 1.062) but not from traffic sources. In general, nontraffic sources contributed more to total air pollution levels than national traffic sources.

CONCLUSIONS

PM2.5 and UFP from traffic and nontraffic sources were associated with increased risk of MI, with nontraffic sources being the dominant source of exposure and morbidity. https://doi.org/10.1289/EHP10556.

Long-term exposure to ambient particulate matter and stroke etiology: Results from the Women's Health Initiative

BACKGROUND

Ambient particulate matter (PM) air pollution is a leading cause of global disability and accounts for an annual 2.9 million deaths globally. PM is established as an important risk factor for cardiovascular disease, however the evidence supporting a link specifically between long-term exposure to ambient PM and incident stroke is less clear. We sought to evaluate the association of long-term exposure to different size fractions of ambient PM with incident stroke (overall and by etiologic subtypes) and cerebrovascular deaths within the Women's Health Initiative, a large prospective study of older women in the US.

METHODS

We studied 155,410 postmenopausal women without previous cerebrovascular disease enrolled into the study between 1993 and 1998, with follow-up through 2010. We assessed geocoded participant address-specific concentrations of ambient PM (fine [PM2.5], respirable [PM10] and coarse [PM10-2.5]), as well as nitrogen dioxide [NO2] using spatiotemporal models. We classified hospitalization events into ischemic, hemorrhagic, or other/unclassified stroke. Cerebrovascular mortality was defined as death from any stroke etiology. We used Cox proportional hazard models to calculate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for individual and neighborhood-level characteristics.

RESULTS

During a median follow-up time of 15 years, participants experienced 4,556 cerebrovascular events. The hazard ratio for all cerebrovascular events was 2.14 (95% CI: 1.87, 2.44) comparing the top versus bottom quartiles of PM2.5. Similarly, there was a statistically significant increase in events comparing the top versus bottom quartiles of PM10 and NO2 (HR: 1.17; 95% CI: 1.03, 1.33 and HR:1.26; 95% CI: 1.12, 1.42). The strength of association did not vary substantially by stroke etiology. There was little evidence of an association between PMcoarse and incident cerebrovascular events.

CONCLUSIONS

Long-term exposure to fine (PM2.5) and respirable (PM10) particulate matter as well as NO2 was associated with a significant increase of cerebrovascular events among postmenopausal women. Strength of the associations were consistent by stroke etiology.

Air pollution and myocardial infarction; effect modification by sociodemographic and environmental factors. A cohort study from Denmark

Air pollution is associated with increased risk of myocardial infarction (MI), but it is unresolved to what extent the association is modified by factors such as socioeconomic status, comorbidities, financial stress, residential green space, or road traffic noise. We formed a cohort of all (n = 1,964,702) Danes, aged 50-85 years, with 65,311 cases of MI during the followed-up period 2005-2017. For all participants we established residential five-year running average exposure to particulate matter <2.5  μm (PM_2.5), ultrafine particles (UFP, <0.1  μm), elemental carbon (EC) and nitrogen dioxide (NO₂). We evaluated risk in population strata, using Aalen additive hazards models to estimate absolute risk and Cox proportional hazards models to estimate relative risk of MI with 95% confidence intervals (CI). PM_2.5 and the other pollutant were associated with MI. Lower education and lower income were associated with higher absolute risks of MI from air pollution, whereas no clear effect modification was apparent for relative risk estimates. For example, 5 μg/m³ higher PM_2.5 was associated with HR for MI of 1.16 (95% CI: 1.10-1.22) among those with only mandatory education and 1.13 (95% CI: 1.03-1.24) among those with long education. The corresponding rate differences per 100,000 person years were 243 (95% CI: 216-271) and 358 (95% CI: 338-379), respectively. Higher level of comorbidity was consistently across all four pollutants associated with both higher absolute and relative risk of MI. In conclusion, people with comorbid conditions or of lower SES appeared more vulnerable to long-term exposure to air pollution and more cases of MI may be prevented by focused interventions in these groups.

Long-term exposure to ambient air pollution, circadian syndrome and cardiovascular disease: A nationwide study in China

OBJECTIVES

Epidemiological evidence suggests associations between ambient air pollution and cardiovascular disease (CVD), while circadian rhythm dysregulation, presented by circadian syndrome (CircS), is emerging as a new proxy to cardiovascular disorder that could provide a bridge between them. The present study aims to clarify the effect of high levels ambient air pollution exposure on CircS and CVD in China.

METHODS

From the China Health and Retirement Longitudinal Study, we recruited 9116 Chinese participants in 2011 and followed them to 2015. A spatiotemporal model was applied to estimate exposure to particles with diameters ≤2.5 μm (PM_2.5). The variable CircS was defined based on 7 components, including the 5 components used to define metabolic syndrome as well as other two components, lack of sleep and depression. The associations between PM_2.5 exposure and prevalent CircS as well as incident CVD were modeled via logistic regression analysis displaying odds ratios (ORs) and 95 % CIs (confidence intervals). A mediation analysis was undertaken to identify the potential mediating role of CircS between PM_2.5 exposure and CVD.

RESULTS

The mean age (standard deviation) was 59 (9) and 48.22 % were male. The OR (95 % CI) between the highest (Q4) and the lowest (Q1) quartile of PM_2.5 exposure for CircS was 1.13 (1.01-1.28) in 2011 and 1.44 (1.22-1.72) in 2015. The cumulative effect of the components of CircS became more obvious with the increase of the PM_2.5 quartile exposure. For the Q4 versus Q1 of PM_2.5 increment, the multivariate-adjusted OR (95 % CI) was 1.66 (1.20-2.29) for CVD incidence. CircS partially mediated the association between PM_2.5 exposure and CVD.

CONCLUSIONS

Exposure to PM_2.5 is a risk factor for CircS and CVD, and the effect of PM_2.5 on CVD may be explained by CircS. Improving air quality would have high value in preventing CircS as well as CVD in public health.

Potential causal links between long-term ambient particulate matter exposure and cardiovascular mortality: New evidence from a large community-based cohort in South China

BACKGROUND

Cardiovascular disease (CVD) mortality is associated with long-term particulate matter (PM) exposure. However, evidence from large, highly-exposed population cohort and observational-data-based causal inference approaches remains limited.

AIMS

We examined the potential causal links between PM exposure and the CVD mortality in South China.

METHODS

580,757 participants were recruited during 2009-2015 and followed up through 2020. Satellite-based annual concentrations of PM_2.5, PM₁₀, and PM_coarse (i.e., PM₁₀ - PM_2.5) at 1 km² spatial resolution were estimated and assigned to each participant. Marginal structural Cox models with time-varying covariates, adjusted using inverse probability weighting, were developed to evaluate the association between prolonged PM exposure and CVD mortality.

RESULTS

For overall CVD mortality, the hazard ratios and 95% confidence interval for each 1 μg/m³ increase in the annual average concentration of PM_2.5, PM₁₀, and PM_coarse were 1.033 (1.028-1.037), 1.028 (1.024-1.032), and 1.022 (1.012-1.033), respectively. All three PMs were linked to a higher mortality risk for myocardial infarction and ischemic heart disease (IHD). The mortality risk of chronic IHD and hypertension was linked to PM_2.5 and PM₁₀. Significant association between PM_coarse and other heart disease mortality was also observed. The older, women, less-educated participants, or inactive participants exhibited particularly higher susceptibility. Participants who were generally exposed to PM₁₀ concentrations below 70 μg/m³ were more vulnerable to PM_2.5-, PM₁₀- and PM_coarse-CVD mortality risks.

CONCLUSION

This large cohort study provides evidence for the potential causal links between increased CVD mortality and ambient PM exposure, as well as socio-demographics linked to the highest vulnerability.

Ambient Air Pollution and Stroke: An Updated Review

Despite recent advances in treatment and prevention, stroke remains a leading cause of morbidity and mortality. There is a critical need to identify novel modifiable risk factors for disease, including environmental agents. A body of evidence has accumulated suggesting that elevated levels of ambient air pollutants may not only trigger cerebrovascular events in susceptible people (short-term exposures) but also increase the risk of future events (long-term average exposures). This review assesses the updated evidence for both short and long-term exposure to ambient air pollution as a risk factor for stroke incidence and outcomes. It discusses the potential pathophysiologic mechanisms and makes recommendations to mitigate exposure on a personal and community level. The evidence indicates that reduction in air pollutant concentrations represent a significant population-level opportunity to reduce risk of cerebrovascular disease.

Health risk assessment for particulate matter: application of AirQ+ model in the northern Caribbean region of Colombia

Air pollution is considered the world's most important environmental and public health risk. The annual exposure for particulate matter (PM) in the northern Caribbean region of Colombia between 2011 and 2019 was determined using PM records from 25 monitoring stations located within the area. The impact of exposure to particulate matter was assessed through the updated Global Burden of Disease health risk functions using the AirQ+ model for mortality attributable to acute lower respiratory disease (in children ≤ 4 years); mortality in adults aged > 18 years old attributable to chronic obstructive pulmonary disease, ischaemic heart disease, lung cancer, and stroke; and all-cause post-neonatal infant mortality. The proportions of the prevalence of bronchitis in children and the incidence of chronic bronchitis in adults attributable to PM exposure were also estimated for the population at risk. Weather Research and Forecasting-California PUFF (WRF-CALPUFF) modeling systems were used to estimate the spatiotemporal trends and calculate mortality relative risk due to prolonged PM2.5 exposure. Proportions of mortality attributable to long-term exposure to PM2.5 were estimated to be around 11.6% of ALRI deaths in children ≤ 4 years of age, 16.1% for COPD, and 26.6% for IHD in adults. For LC and stroke, annual proportions attributable to PM exposure were estimated to be 9.1% and 18.9%, respectively. An estimated 738 deaths per year are directly attributed to particulate matter pollution. The highest number of deaths per year is recorded in the adult population over 18 years old with a mean of 401 events. The mean risk in terms of the prevalence of bronchitis attributable to air pollution in children was determined to be 109 per 100,000 inhabitants per year. The maximum RR values for mortality (up 1.95%) from long-term PM2.5 exposure were predicted to correspond to regions downwind to the industrial zone.

Supplementary information

The online version contains supplementary material available at 10.1007/s11869-023-01304-5.

Association between short-term exposure to ambient air pollution and heart failure: An updated systematic review and meta-analysis of more than 7 million participants

Introduction

Exposure to air pollution has been linked to the mortality of heart failure. In this study, we sought to update the existing systematic review and meta-analysis, published in 2013, to further assess the association between air pollution and acute decompensated heart failure, including hospitalization and heart failure mortality.

Methods

PubMed, Web of Science, EMBASE, and OVID databases were systematically searched till April 2022. We enrolled the studies regarding air pollution exposure and heart failure and extracted the original data to combine and obtain an overall risk estimate for each pollutant.

Results

We analyzed 51 studies and 7,555,442 patients. Our results indicated that heart failure hospitalization or death was associated with increases in carbon monoxide (3.46% per 1 part per million; 95% CI 1.0233-1.046, P < 0.001), sulfur dioxide (2.20% per 10 parts per billion; 95% CI 1.0106-1.0335, P < 0.001), nitrogen dioxide (2.07% per 10 parts per billion; 95% CI 1.0106-1.0335, P < 0.001), and ozone (0.95% per 10 parts per billion; 95% CI 1.0024-1.0166, P < 0.001) concentrations. Increases in particulate matter concentration were related to heart failure hospitalization or death (PM_2.5 1.29% per 10 μg/m³, 95% CI 1.0093-1.0165, P < 0.001; PM₁₀ 1.30% per 10 μg/m³, 95% CI 1.0102-1.0157, P < 0.001).

Conclusion

The increase in the concentration of all pollutants, including gases (carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone) and particulate matter [(PM_2.5), (PM₁₀)], is positively correlated with hospitalization rates and mortality of heart failure.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021256241.

Long-term exposure to ambient ozone and mortality in a population-based cohort of South Korea: Considering for an alternative exposure time metric

Studies on the health effects of long-term ozone exposure remain limited with mixed results. One potential source of this inconsistency is the difference in exposure time metrics. This study aimed to investigate the association between long-term exposure to ambient ozone and mortality in South Korea, using different exposure metrics. We also examined whether heterogeneity between previous studies was due to the different exposure metrics. The study population comprised 179,806 participants from the National Health Insurance Service-National Sample Cohort (2002-2015) residing in seven major cities in South Korea. Several ozone exposure metrics (year-round 24-h, year-round 8-h, warm-season 24-h, and warm-season 8-h) were calculated. Time-varying Cox proportional hazards models were used to estimate the association between ozone and all-cause and cause-specific mortalities. Random-effect meta-analysis and meta-regression analysis were performed to pool the effect estimates of previous studies and examine whether the exposure metric can explain the between-study heterogeneity. The hazard ratios (HRs) per 10 ppb increment in year-round 24-h ozone for all-cause (HR, 1.18; 95% CI, 1.07-1.29) and circulatory (HR, 1.52; 95% CI, 1.25-1.84) mortality were higher than those of the other metrics. Year-round 8-h ozone exhibited the largest association with respiratory mortality (HR, 1.43; 95% CI, 1.04-1.96). A meta-analysis of 29 previous studies and the present study showed the largest HR for all-cause mortality from studies using year-round 8-h exposure (HR, 1.014; 95% CI, 0.994-1.033). The exposure metric was significantly associated with effect estimates in the multivariable meta-regression model. In conclusion, in the population-based cohort in South Korea, we found positive associations between several long-term ozone exposure metrics and mortality. The different ozone exposure metrics exhibited heterogeneous effect estimates. A year-round 24-h average ozone metric also could be considered an alternative long-term standard for ozone.

Long-term air pollution exposure and incident stroke in American older adults: A national cohort study

Aims

Stroke is a leading cause of death and disability for Americans, and growing evidence suggests that air pollution may play an important role. To facilitate pollution control efforts, the National Academy of Sciences and the World Health Organization have prioritized determining which air pollutants are most toxic. However, evidence is limited for the simultaneous effects of multiple air pollutants on stroke.

Methods and results

We constructed a nationwide population-based cohort study, using the Medicare Chronic Conditions Warehouse (2000-2017) and high-resolution air pollution data, to investigate the impact of long-term exposure to ambient PM2.5, NO2, and ground-level O3 on incident stroke. Hazard ratios (HR) for stroke incidence were estimated using single-, bi-, and tri-pollutant Cox proportional hazards models. We identified ~2.2 million incident stroke cases among 17,443,900 fee-for-service Medicare beneficiaries. Per interquartile range (IQR) increase in the annual average PM2.5 (3.7 μg/m3), NO2 (12.4 ppb), and warm-season O3 (6.5 ppb) one-year prior to diagnosis, the HRs were 1.022 (95% CI: 1.017-1.028), 1.060 (95% CI: 1.054-1.065), and 1.021 (95% CI: 1.017-1.024), respectively, from the tri-pollutant model. There was strong evidence of linearity in concentration-response relationships for all three air pollutants in single-pollutant models. This linear relationship remained robust for NO2 and O3 in tri-pollutant models while the effect of PM2.5 attenuated at the lower end of concentrations.

Conclusion

Using a large nationwide cohort, our study suggests that long-term exposure to PM2.5, NO2, and O3 may independently increase the risk of stroke among the US elderly, among which traffic-related air pollution plays a particularly crucial role.

Adverse effects of air pollution-derived fine particulate matter on cardiovascular homeostasis and disease

Air pollution is a rapidly growing major health concern around the world. Atmospheric particulate matter that has a diameter of less than 2.5 µm (PM2.5) refers to an air pollutant composed of particles and chemical compounds that originate from various sources. While epidemiological studies have established the association between PM2.5 exposure and cardiovascular diseases, the precise cellular and molecular mechanisms by which PM2.5 promotes cardiovascular complications are yet to be fully elucidated. In this review, we summarize the various sources of PM2.5, its components, and the concentrations of ambient PM2.5 in various settings. We discuss the experimental findings to date that evaluate the potential adverse effects of PM2.5 on cardiovascular homeostasis and function, and the possible therapeutic options that may alleviate PM2.5-driven cardiovascular damage.

Health effects of exposure to sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide between 1980 and 2019: A systematic review and meta-analysis

The burden of disease attributed to the indoor exposure to sulfur dioxide (SO₂ ), nitrogen dioxide (NO₂ ), ozone (O₃ ), and carbon monoxide (CO) is not clear, and the quantitative concentration-response relationship is a prerequisite. This is a systematic review to summarize the quantitative concentration-response relationships by screening and analyzing the polled effects of population-based epidemiological studies. After collecting literature published between 1980 and 2019, a total of 19 health outcomes in 101 studies with 182 health risk estimates were recruited. By meta-analysis, the leave-one-out sensitivity analysis and Egger's test for publication bias, the robust and reliable effects were found for SO₂ (per 10 μg/m³ ) with chronic obstructive pulmonary diseases (COPD) (pooled relative risks [RRs] 1.016, 95% CI: 1.012-1.021) and cardiovascular diseases (CVD) (RR 1.012, 95%CI: 007-1.018), respectively. NO₂ (per 10 μg/m³ ) had the pooled RRs for childhood asthma, preterm birth, lung cancer, diabetes, and COPD by 1.134 (1.084-1.186), 1.079 (1.007-1.157), 1.055 (1.010-1.101), 1.019 (1.009-1.029), and 1.016 (1.012-1.120), respectively. CO (per 1 mg/m³ ) was significantly associated with Parkinson's disease (RR 1.574, 95% CI: 1.069-2.317) and CVD (RR 1.024, 95% CI: 1.011-1.038). No robust effects were observed for O₃ . This study provided evidence and basis for further estimation of the health burden attributable to the four gaseous pollutants.

Ambient gaseous pollutant exposure and incidence of visual impairment among children and adolescents: findings from a longitudinal, two-center cohort study in China

Evidence on the effects of exposure to ambient gaseous pollutants on children's vision was consistently scarce. We aimed to explore the effect of ambient gaseous pollutant exposure on the incidence of visual impairment (VI) in children. From 2005 to 2018, a total of 340,313 children without VI participated in a longitudinal and two-center dynamic cohort. The logMAR acuity was used to assess visual function. The space-time extremely randomized trees model was used to estimate SO₂ and CO exposures levels. The association between SO₂ and CO and VI risks among children was assessed using a proportional hazards model with a restricted cubic spline. Subgroup analyses stratified by gender and grades were used to investigate the differences in an association of SO₂ and CO exposures with childhood VI. A total of 158381 (46.54%) children experienced an new incident VI. A ten-unit (10 μg/m³) increase in SO₂ exposure concentrations was significantly associated with a 1.70 times higher risk of childhood VI. In addition, a 0.1-unit (0.1 mg/m³) increase in CO exposure was significantly associated with a 1.22 times higher risk of childhood VI. The positive association between ambient gaseous pollutants (including SO₂ and CO exposures) and childhood VI risks remained even after adjusting for other environmental variables. An increase in the incidence of VI in children was positively linked to SO₂ and CO exposure. Such evidence might aid governments in developing strategies to interfere with children's eyesight by decreasing air pollution and changing school curricula.

The Impact of Fine Particulate Matter 2.5 on the Cardiovascular System: A Review of the Invisible Killer

Air pollution exerts several deleterious effects on the cardiovascular system, with cardiovascular disease (CVD) accounting for 80% of all premature deaths caused by air pollution. Short-term exposure to particulate matter 2.5 (PM_2.5) leads to acute CVD-associated deaths and nonfatal events, whereas long-term exposure increases CVD-associated risk of death and reduces longevity. Here, we summarize published data illustrating how PM_2.5 may impact the cardiovascular system to provide information on the mechanisms by which it may contribute to CVDs. We provide an overview of PM_2.5, its associated health risks, global statistics, mechanistic underpinnings related to mitochondria, and hazardous biological effects. We elaborate on the association between PM_2.5 exposure and CVD development and examine preventive PM_2.5 exposure measures and future strategies for combating PM_2.5-related adverse health effects. The insights gained can provide critical guidelines for preventing pollution-related CVDs through governmental, societal, and personal measures, thereby benefitting humanity and slowing climate change.

Air Pollution and Its Devastating Effects on the Central Nervous System

Air pollution is a real public health problem, it being one of the five most common causes of mortality in developing countries. However, pollution studies have focused on the cardiovascular and pulmonary systems in recent decades. Recently, researchers have moved towards a new direction, tracing a direct link between pollution and stroke. Stroke has many known risk factors such as smoking, a sedentary lifestyle, and hypertension. Pollution is universally widespread, already a matter of public interest, so that, although intuitive, it is difficult to connect the two. The particles found in the air that we breathe, regardless of their origin, can attack the body in different ways, causing inflammation, and triggering a true cascade of phenomena that end up attacking the central nervous system and other organs. This article tries to explain the series of phenomena that determine the harmful effect of particles present in the air, with an increased focus on the central nervous system and especially on strokes. A deeper understanding of these phenomena helps in guiding future studies and finding viable solutions to protect people at risk.

The long-term effect of exposure to respirable particulate matter on the incidence of myocardial infarction: a systematic review and meta-analysis study

Although several studies have investigated the long-term association of respirable particulate matter (PM ≤ 10 µm) with the incidence of myocardial infarction (MI), this association is inconclusive or even contradictory. This systematic review and meta-analysis study aimed to quantify the long-term effect of exposure to respirable PM on the incidence of MI. To find relevant publications, online databases, including Scopus, PubMed, and Web of Science, were searched on October 10, 2021. A random-effect model was used to calculate the pooled hazard ratio (HR) and 95% confidence interval (95% CI) of MI across studies. Heterogeneity was presented with reporting I² index. Of 4591 records found in the primary searching, the number of 24 prospective cohort studies with more than 70 million participants was included. The pooled HR (95% CI) of MI per 1 µg/m³ increment of respirable PM was estimated as 1.01 (1.00, 1.01). Subgroup analyses according to aerodynamic diameter of PM showed an only significant stronger risk of MI per 1 µg/m³ increase in PM with aerodynamic diameter < 2.5 µm (HR = 1.01, 95% CI = 1.00, 1.01). No sex difference was found in the association of respirable PM with MI incidence. There was only a significant association among studies defined MI as ICD-10: I21 code (HR = 1.01, 95% CI = 1.00, 1.01) and studies defined MI as ICD-10: I21-22 (HR = 1.02, 95% CI = 1.00, 1.04). No significant publication bias was observed across studies. In conclusion, this study confirms a significant association between long-term exposure to respirable PM air pollution and development of MI.

Effects of Fine Particulate Matter on Cardiovascular Disease Morbidity: A Study on Seven Metropolitan Cities in South Korea

Objectives: The primary purpose of this study is to analyze the relationship between the first occurrence of hospitalization for cardiovascular disease (CVD) and particulate matter less than 2.5 μm in diameter (PM2.5) exposure, considering average PM2.5 concentration and the frequency of high PM2.5 concentration simultaneously.

Methods: We used large-scale cohort data from seven metropolitan cities in South Korea. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using the Cox proportional-hazards model, including annual average PM2.5 and annual hours of PM2.5 concentration exceeding 55.5 μg/m³ (FH55).

Results: We found that the risk was elevated by 11.6% (95% CI, 9.7–13.6) for all CVD per 2.9 μg/m³ increase of average PM2.5. In addition, a 94-h increase in FH55 increased the risk of all CVD by 3.8% (95% CI, 2.8–4.7). Regarding stroke, we found that people who were older and had a history of hypertension were more vulnerable to PM2.5 exposure.

Conclusion: Based on the findings, we conclude that accurate forecasting, information dissemination, and timely warning of high concentrations of PM2.5 at the national level may reduce the risk of CVD occurrence.

A cohort study evaluating the risk of stroke associated with long-term exposure to ambient fine particulate matter in Taiwan

BACKGROUND

Evidences have shown that the stroke risk associated with long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) varies among people in North America, Europe and Asia, but studies in Asia rarely evaluated the association by stroke type. We examined whether long-term exposure to PM_2.5 is associated with developing all strokes, ischemic stroke and hemorrhagic stroke.

METHODS

The retrospective cohort study consisted of 1,362,284 adults identified from beneficiaries of a universal health insurance program in 2011. We obtained data on air pollutants and meteorological measurements from air quality monitoring stations across Taiwan in 2010-2015. Annual mean levels of all environmental measurements in residing areas were calculated and assigned to cohort members. We used Cox proportional hazards models to estimate hazard ratio (HR) and 95% confidence interval (CI) of developing stroke associated with 1-year mean levels of PM_2.5 at baseline in 2010, and yearly mean levels from 2010 to 2015 as the time-varying exposure, adjusting for age, sex, income and urbanization level.

RESULTS

During a median follow-up time of 6.0 years, 12,942 persons developed strokes, 9919 (76.6%) were ischemic. The adjusted HRs (95% CIs) per interquartile range increase in baseline 1-year mean PM_2.5 were 1.03 (1.00-1.06) for all stroke, 1.06 (1.02-1.09) for ischemic stroke, and 0.95 (0.89-1.10) for hemorrhagic stroke. The concentration-response curves estimated in the models with and without additional adjustments for other environmental measurements showed a positively linear association between baseline 1-year mean PM_2.5 and ischemic stroke at concentrations greater than 30 μg/m³, under which no evidence of association was observed. There was an indication of an inverse association between PM_2.5 and hemorrhagic stroke, but the association no longer existed after controlling for nitrogen dioxide or ozone. We found similar shape of the concentration-response association in the Cox regression models with time-varying PM_2.5 exposures.

CONCLUSION

Long-term exposure to PM_2.5 might be associated with increased risk of developing ischemic stroke. The association with high PM_2.5 concentrations remained significant after adjustment for other environmental factors.

COVID-19, air quality and space monitoring

Due to the worldwide spread of the coronavirus disease 2019 (COVID-19), human mobility and economic activity have slowed down considerably since early 2020. A relatively high number of those infected develop serious pneumonia leading to progressive respiratory failure, system disease and often death. Apart from close human-to-human contact, the acceleration and global diffusion of this pandemic has been shown to be associated with changes in atmospheric chemistry and air pollution by microscopic particulate matter (PM). Breathing air with high concentrations of nitrogen dioxide and PM can result in over-expression of the angiotensin converting enzyme-2 (ACE-2) leading to stress of organs, such as heart and kidneys. Satellite monitoring can play a crucial role in spatio-temporal surveillance of the disease by producing data on pollution as proxy for industrial activity, transport and traffic circulation. Real-time monitoring of COVID-19 in air and chemical pollution of the atmospheric boundary layer available from Earth-observing satellites commuting with Health Information Systems (HIS) would be useful for decision makers involved with public health.

Health Effects of Long-Term Exposure to Ambient PM2.5 in Asia-Pacific: a Systematic Review of Cohort Studies

Abstract

Purpose of Review

Health effects of long-term exposure to ambient PM_2.5 vary with regions, and 75% of the deaths attributable to PM_2.5 were estimated in Asia-Pacific in 2017. This systematic review aims to summarize the existing evidence from cohort studies on health effects of long-term exposure to ambient PM_2.5 in Asia-Pacific.

Recent Findings

In Asia-Pacific, 60 cohort studies were conducted in Australia, Mainland China, Hong Kong, Taiwan, and South Korea. They consistently supported associations of long-term exposure to PM_2.5 with increased all-cause/non-accidental and cardiovascular mortality as well as with incidence of cardiovascular diseases, type 2 diabetes mellitus, kidney diseases, and chronic obstructive pulmonary disease. Evidence for other health effects was limited. Inequalities were identified in PM_2.5-health associations.

Summary

To optimize air pollution control and public health prevention, further studies need to assess the health effects of long-term PM_2.5 exposure in understudied regions, the health effects of long-term PM_2.5 exposure on mortality and risk of type 2 diabetes mellitus, renal diseases, dementia and lung cancer, and inequalities in PM_2.5-health associations. Study design, especially exposure assessment methods, should be improved.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40572-022-00344-w.

Environmental air pollution and chronic rhinosinusitis: A systematic review

Objective

Chronic rhinosinusitis (CRS) is a highly prevalent and burdensome disease. The pathophysiology is not fully elucidated, but environmental pollutants have been suggested to impact the inflammatory component of the disease process. This review aims to summarize the role of environmental pollution in CRS onset and disease severity.

Methods

A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus databases were queried in August 2021. Original articles reporting on air pollution exposure in CRS were included. Other forms of sinonasal disease were excluded.

Results

Literature search produced 11,983 articles, of which 10 met inclusion criteria. Outcomes evaluated included incidence/prevalence, disease severity, quality of life, and histopathologic/microbial changes. Air pollutant exposure was associated with higher odds of CRS, particularly with particulate matter (PM) exposure. Increasing air pollution exposure was also associated with worsened disease severity and detectable histopathologic changes. Impact on quality of life was less clear.

Conclusion

Air pollution (particularly PM) is correlated with CRS incidence/prevalence and disease severity, with evidence of histopathologic changes in CRS tissue samples. Further research is warranted to better understand the mechanisms by which air pollution components may cause CRS and type 2 inflammation.

Level of Evidence

3a

Recent evidence suggests a role for air pollution in the onset and severity of CRS, most notably with relation to PM_2.5 exposure. This systematic review supports previous in vitro and in vivo models of pollution in CRS. This study further adds to the existing body of literature demonstrating the many negative health impacts of exposure to air pollution, including impacts on upper airway disease, lower airway disease, cardiac disease, and overall morbidity and mortality.

Association between satellite-based estimates of long-term PM2.5 exposure and cardiovascular disease: evidence from the Indonesian Family Life Survey

Exposure to particulate matter with a diameter < 2.5 µm (PM2.5) increases the risk of cardiovascular disease (CVD), which is the leading cause of both morbidity and mortality in Indonesia, accounting for one-third of all deaths. Indonesian authorities started to monitor PM2.5 levels in urban areas in 2015. However, there is still no study examining the association between long-term PM2.5 exposure and CVD in Indonesia. In this study, we combined PM2.5 data and health survey data. Long-term (2000-2007) exposure to PM2.5 was measured based on satellite-derived aerosol optical depth measurements (1 × 1 km2) that could be used to predict ground-level PM2.5 concentrations. Population data on residents of Sumatra Island were obtained from the fourth wave of the Indonesian Family Life Survey (IFLS). A cross-sectional study was performed with 2324 participants who were aged ≥ 40 years old, and a report of doctor-diagnosed CVD determined CVD status. We used logistic regression to analyze the association between PM2.5 and CVD prevalence, adjusting for multiple covariates. Of the sample, 52.1% were women, and 47.9% were men. The sample was divided into those aged 40-59 (adults) and those ≥ 60 (older adults). The CVD prevalence was 4.05% (n = 94), with a mean (standard deviation) PM2.5 concentration of 14.4 (6.4) µg/m3. In adjusted models, a 10-µg/m3 increase in annual average PM2.5 levels was associated with 29% higher odds of having CVD (odds ratio = 1.29; 95% confidence interval: 1.02, 1.47). In this population-based IFLS data, long-term exposure to PM2.5 is associated with a higher prevalence of CVD in Sumatera, Indonesia.

Ambient air pollution and the risk of acute myocardial infarction and stroke: A national cohort study

We used a large national cohort in Canada to assess the incidence of acute myocardial infarction (AMI) and stroke hospitalizations in association with long-term exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃). The study population comprised 2.7 million respondents from the 2006 Canadian Census Health and Environment Cohort (CanCHEC), followed for incident hospitalizations of AMI or stroke between 2006 and 2016. We estimated 10-year moving average estimates of PM_2.5, NO₂, and O₃, annually. We used Cox proportional hazards models to examine the associations adjusting for various covariates. For AMI, each interquartile range (IQR) increase in exposure was found to be associated with a hazard ratio of 1.026 (95% CI: 1.007-1.046) for PM_2.5, 1.025 (95% CI: 1.001-1.050) for NO₂, and 1.062 (95% CI: 1.041-1.084) for O₃, respectively. Similarly, for stroke, an IQR increase in exposure was associated with a hazard ratio of 1.078 (95% CI: 1.052-1.105) for PM_2.5, 0.995 (95% CI: 0.965-1.030) for NO₂, and 1.055 (95% CI: 1.028-1.082) for O₃, respectively. We found consistent evidence of positive associations between long-term exposures to PM_2.5, and O₃, and to a lesser degree NO₂, with incident AMI and stroke hospitalizations.

Validity evaluation of indirect adjustment method for multiple unmeasured confounders: A simulation and empirical study

BACKGROUND

An indirect adjustment method was developed to control for unmeasured confounders in a large administrative cohort study. A previous study that proposed the indirect adjustment method assessed the validity of the method by simulations but did not consider the direction of bias and scenarios with multiple missing confounders. In this study, we evaluated the direction and the magnitude of bias of the indirect adjustment method with multiple correlated unmeasured confounders using simulation and empirical datasets.

METHODS

A simulation study was conducted to compare the bias of the indirect adjustment by varying the number of confounders, magnitude of correlation between confounders, and the number of adjustment variables. An empirical study was conducted by applying the indirect adjustment method to the association between PM₁₀ and mortality using the Korea National Health and Nutrition Examination Survey linked Cause of Death data for 2007-2016.

RESULTS

The simulations of the present study demonstrated that 1) when a confounder is positively associated with both exposure and outcome, indirect adjustment might bias the effect size downward; 2) the magnitude of bias might depend on the correlation between unmeasured confounders; and 3) indirect adjustment for multiple missing confounders at once could result in a higher bias than that for some of the missing confounders. Empirical analyses also showed consistent results, but the bias of indirectly adjusted effect estimates was sometimes larger than that of unadjusted effect estimates.

CONCLUSIONS

The indirect adjustment method is a promising technique to reduce the bias from unmeasured confounding; however, it should be implemented carefully, particularly when there are multiple correlated unmeasured confounders of the same direction.

Associations between ambient fine particulate (PM2.5) exposure and cardiovascular disease: findings from the China Health and Retirement Longitudinal Study (CHARLS)

The evidence regarding the association between long-term fine particulate (PM2.5) exposure and cardiovascular disease (CVD) in developing countries is limited. This study investigated the association between long-term exposure to PM2.5 and the prevalence of CVD among middle-aged and older adults. A total of 13,484 adults ≥ 45 years of age were surveyed in China, and logistic regression models were used to examine the association between PM2.5 and the prevalence of CVD. Furthermore, stratified analyses were conducted to explore potential effect modifiers. In addition, the burden of CVD attributable to PM2.5 was estimated. The analyses revealed that PM2.5 was associated with CVD, with an adjusted odds ratio (OR) of 1.18 (95% confidence interval [CI]: 1.12, 1.26) for each 10 μg/m3 increment in ambient PM2.5. Stratified analyses found that the elderly may be a vulnerable population. It was further estimated that approximately 20.27% (95% CI: 11.86%, 29.96%) of CVD cases could be attributable to PM2.5. This nationwide study confirmed that long-term exposure to PM2.5 was associated with an increased prevalence of CVD in China.

Links between chronic exposure to outdoor air pollution and cardiovascular diseases: a review

Acute exposure to air pollution is associated with an increasing risk of death and cardiovascular disorders. Nonetheless, the impact of chronic exposure to air pollution on the circulatory system is still debated. Here, we review the links of chronic exposure to outdoor air pollution with mortality and most common cardiovascular diseases, in particular during the coronavirus disease 2019 event (COVID-19). We found that recent studies provide robust evidence for a causal effect of chronic exposure to air pollution and cardiovascular mortality. In terms of mortality, the strongest relationship was noted for fine particulate matter, nitrogen dioxide, and ozone. There is also increasing evidence showing that exposure to air pollution, mainly fine particulate matter and nitrogen dioxide, is associated with the development of atherosclerosis, hypertension, stroke, and heart failure. However, available scientific evidence is not strong enough to support associations with cardiac arrhythmias and coagulation disturbances. Noteworthy, for some pollutants, the risk of negative health effects is high for concentrations lower than the limit values recommended by the European Union and Word Health Organization. Efforts to diminish exposure to air pollution and to design optimal methods of air pollution reduction should be urgently intensified and supported by effective legislation and interdisciplinary cooperation.

Air pollution and recurrence of cardiovascular events after ST-segment elevation myocardial infarction

BACKGROUND AND AIMS

The effects of air pollution on discharged patients after ST-segment elevation myocardial infarction (STEMI) still remain uncertain. We examined the association between air pollutants and recurrent cardiovascular events in STEMI survivors.

METHODS

A retrospective cohort of 1641 discharged patients after STEMI was established in 2013 and followed until the end of 2019. Concentrations of air pollutants including fine particles <2.5 μm aerodynamic diameter (PM_2.5), inhalable particles <10 μm aerodynamic diameter (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO) and ozone (O₃) measured by fixed ambient air monitoring stations were collected for exposure assessment. Multivariate-adjusted Cox proportional hazards models were used to estimate the increased risks of recurrent cardiovascular events.

RESULTS

Compared with the first exposure quartile, for short-term exposure, hazard ratios (HRs) of recurrent cardiovascular events associated with the fourth exposure quartiles of PM_2.5, PM₁₀, NO₂, SO₂, CO, and O₃ were 4.06 (95% CI: 2.62-6.30), 3.79 (95% CI: 2.57-5.58), 2.22 (95% CI: 1.67-2.94), 4.47 (95% CI: 3.08-6.48), 3.73 (95% CI: 2.54-5.48), and 5.35 (95% CI: 3.12-9.20), respectively. For long-term exposure, HRs associated with the fourth exposure quartiles of PM_2.5, PM₁₀, NO₂, SO₂, CO, and O₃ were 6.43 (95% CI: 3.60-11.47), 4.77 (95% CI: 2.85-7.99), 3.22 (95% CI: 2.00-5.19), 3.20 (95% CI: 2.05-5.01), 4.44 (95% CI: 2.65-7.45), and 1.07 (95% CI: 0.80-1.42), respectively. The risks of recurrent cardiovascular events brought by air pollutants mostly increased nonlinearly.

CONCLUSIONS

Short- and long-term exposure to air pollutants except ozone increases the risks of recurrent cardiovascular events in STEMI survivors. Better environmental policies and secondary prevention strategies should be developed to protect STEMI survivors as a susceptible population.

Urban fine particulate air pollution exposure promotes atherosclerosis in apolipoprotein E-deficient mice by activating perivascular adipose tissue inflammation via the Wnt5a/Ror2 signaling pathway

Urban fine particulate matter (PM_2.5) is a deleterious risk factor in the ambient air and is recognized to exacerbate atherosclerosis. Perivascular adipose tissue (PVAT) secretes a large number of inflammatory cytokines and plays a crucial role in the pathogenic microenvironment of atherogenesis. However, there is a lack of knowledge about the role of PVAT inflammation in the genesis of PM_2.5-related atherosclerosis. The aim of this research was to probe the latent links between PM_2.5 exposure and PVAT inflammation and further discovered the underlying mechanisms of PM_2.5-triggered atherosclerosis pathogenesis. Apolipoprotein E-deficient (ApoE^-/-) mice were exposed to real-world atmospheric PM_2.5 or filtered clean air for three months, the Wnt5a inhibitor Box5 and the Ror2 inhibitor β-Arrestin2 were applied to verify the possible mechanisms. We noticed that the average daily PM_2.5 mass concentration was 84.27 ± 28.84 μg/m³. PM_2.5 inhalation might significantly expedite the deterioration of atherosclerosis, increase the protein and mRNA expressions of MCP-1, IL-6, TNF-α, Wnt5a, and Ror2 in PVAT tissues, upregulate the distributions of IL-6, TNF-α, MCP-1, and leptin in the histological sections of PVAT, promote lipid deposition in the aorta, elevate the plasma levels of leptin, MCP-1, IL-6, TNF-α, LDL-C, TC, and TG, however, decrease the plasma levels of adiponectin and HDL-C, downregulate the distribution of adiponectin. Nevertheless, these effects caused by PM_2.5 exposure were dramatically diminished after the administration of Box5 or β-Arrestin2. This research illuminated that PVAT inflammation was involved in the PM_2.5-induced atherosclerosis process, as well as lipid deposition, which was closely associated with the activation of the Wnt5a/Ror2 signaling pathway.

Ambient Air Pollution and Cardiorespiratory Outcomes amongst Adults Residing in Four Informal Settlements in the Western Province of South Africa

Few studies have investigated the relationship between ambient air pollution and cardiorespiratory outcomes in Africa. A cross-sectional study comprising of 572 adults from four informal settlements in the Western Cape, South Africa was conducted. Participants completed a questionnaire adapted from the European Community Respiratory Health Survey, and the National Health and Nutrition Examination Survey questionnaire. Exposure estimates were previously modelled using Land-Use Regression for Particulate Matter (PM_2.5) and Nitrogen Dioxide (NO₂) at participants' homes. The median age of the participants was 40.7 years, and 88.5% were female. The median annual NO₂ level was 19.7 µg/m³ (interquartile range [IQR: 9.6-23.7]) and the median annual PM_2.5 level was 9.7 µg/m³ (IQR: 7.3-12.4). Logistic regression analysis was used to assess associations between outcome variables and air pollutants. An interquartile range increase of 5.12 µg/m³ in PM_2.5 was significantly associated with an increased prevalence of self-reported chest-pain, [Odds ratio: 1.38 (95% CI: 1.06-1.80)], adjusting for NO₂, and other covariates. The study found preliminary circumstantial evidence of an association between annual ambient PM_2.5 exposure and self-reported chest-pain (a crude proxy of angina-related pain), even at levels below the South African National Ambient Air Quality Standards.

Estimating the urban environmental impact of gasoline-ethanol blended fuels in a passenger vehicle engine

A large portion of urban emissions in developing countries come from old gasoline vehicles driven in metropolitan areas. The present study aimed to develop models to estimate the environmental impact of different contents of gasoline and ethanol mixtures (pure gasoline; 25, 50, 75% ethanol blended to gasoline; and 100% ethanol) in a flex-fuel engine. We tested the blended fuel using three different speeds and recorded the GHG emissions and engine output data. The data mining approach was used to develop environmental impact predictive models. The ethanol content in gasoline; the engine rotational speed 900, 2000, and 3000 rpm; and λ were used as attributes. The classification target was the environmental impact concerning the CO₂ emission ("low," "average," and "high"). We employed the Random forest algorithm to develop predictive models. The mean values of CO₂ concentrations for all studied fuel content were above 2.47% of the volume. The trees' models (accuracy 73%, κ =0.61) showed three alternatives for predicting the environmental impact based on the ethanol blend, the engine rotation, λ, and the air-fuel ratio. Such models might help policymakers develop educational campaigns to reduce short- and medium-term urban commuter traffic pollution in countries that lack suitable urban transportation.